COMPAct: Actuator design framework

This repository provides an implementation of the paper:

COMPAct: Computational Optimization and Automated Modular design of Planetary Actuators
Aman Singh, Deepak Kapa, Suryank Joshi, and Shishir Kolathaya
IEEE International Conference on Robotics and Automation, 2026
Video-Overview

---

This framework provides the following features:

1. Optimize planetary gearbox parameters for a given motor across the following gearbox types:

   • Single Stage Planetary Gearbox (SSPG),
   • Compound Planetary Gearbox (CPG),
   • Wolfrom Planetary Gearbox (3K)(WPG), and
   • Double Stage Planetary Gearbox (DSPG).

2. Perform multi-objective optimization to minimize actuator mass and axial width while maximizing efficiency.

3. Automatically generate parametric actuator CAD from optimization results, enabling direct 3D printing without manual redesign.

---

✅ Supported Hardware

Supported Motors

Motor Code	Description
U8	T-motor U8
U10	T-motor U10+
U12	T-motor U12
MN8014	T-motor MN8014
VT8020	Vector Techniques 8020
MAD_M6C12	MAD Components M6C12

Supported Gearbox Topologies

Type	Description
sspg	Single-Stage Planetary Gearbox
cpg	Compound Planetary Gearbox
wpg	Wolfrom Planetary Gearbox (3K)
dspg	Double-Stage Planetary Gearbox

---

💻 Setup & Requirements

System Requirements

• Python 3.x
• SolidWorks 2024 (or higher) – Required for CAD automation features.

Recommended Terminal

• Windows: Git Bash is highly recommended.
• Linux/macOS: Default terminal.

1. Installation

Clone the repository and install the dependencies:

# Clone the repository
git clone https://github.com/singhaman1750/COMPAct-Actuator_design_framework.git

# Enter the directory
cd COMPAct-Actuator_design_framework 

# Install required packages
pip install numpy matplotlib pandas

2. Extract CAD Files (Optional)

Due to file size limits, CAD files are zipped. You must extract them before running the framework.

NOTE: If you only need the optimized gear parameters (teeth count, module, etc.), you can skip this step. Extraction is only required if you intend to use the automated 3D modeling.

1. Navigate to the CADs directory.
2. Inside each gearbox folder (e.g., CADs/SSPG/), unzip the archive (e.g., sspg_actuator.zip) into the same directory.

Your directory structure should look like this after extraction:

COMPAct-Actuator_design_framework/
└── CADs/
    ├── SSPG/sspg_actuator/sspg_actuator/...
    ├── CPG/cpg_actuator/cpg_actuator/...
    ├── DSPG/dspg_actuator/dspg_actuator/...
    └── WPG/wpg_actuator/wpg_actuator/...

---

🚀 Usage

Step 1: Run Optimization

Run the Python script from the root directory to generate optimal gear parameters.

Syntax:

python actOpt.py <motor> <gearbox> <ratio>

• <motor>: U8, U10, U12, MN8014, VT8020, MAD_M6C12
• <gearbox>: sspg, cpg, dspg, wpg
• <ratio>: Must be a value > 2.

Example: To optimize a T-motor U8 with a Single-Stage Planetary Gearbox and a ratio of 6.5:

python actOpt.py U8 sspg 6.5

Step 2: View Results

The script will output the optimal geometric parameters directly in the terminal:

Running optimization:
  Motor       : U8
  Gearbox     : sspg
  Gear Ratio  : 6.5
Time taken: 0.0196 sec
Optimization Completed.
-------------------------------
Optimal Parameters:
Number of teeth: Sun(Ns): 23 , Planet(Np): 52 , Ring(Nr): 127 , Module(m): 0.6 , NumPlanet(n_p): 3
---
Gear Ratio(GR): 6.52 : 1
-------------------------------

Detailed parameter files (used by SolidWorks) are automatically generated in the following locations:

• SSPG: CADs/SSPG/sspg_equations.txt
• CPG: CADs/CPG/cpg_equations.txt
• DSPG: CADs/DSPG/dspg_equations.txt
• WPG: CADs/WPG/wpg_equations.txt

Step 3: CAD Automation

NOTE: If you skipped the CAD extraction, you can stop at Step 2.

1. Open SolidWorks.
2. Open the assembly file (.SLDASM) for your specific gearbox type:
   • SSPG: CADs/SSPG/sspg_actuator/sspg_actuator/sspg_actuator.SLDASM
   • (Paths for CPG, DSPG, and WPG follow the same folder pattern)
3. Click the Rebuild (Traffic Light) icon.
4. The 3D model will automatically update to reflect the calculated parameters.

Step 4: Manufacturing

• 3D Printing: Export the updated plastic parts to .STL format.
• Bearings: Check the updated CAD model to identify which standard bearings are required for your specific configuration.

---

📄 Citation

If you use this framework in your research, please cite:

@misc{singh2025compact,
      title={COMPAct: Computational Optimization and Automated Modular design of Planetary Actuators}, 
      author={Aman Singh and Deepak Kapa and Suryank Joshi and Shishir Kolathaya},
      year={2025},
      eprint={2510.07197},
      archivePrefix={arXiv},
      primaryClass={cs.RO},
      url={[https://arxiv.org/abs/2510.07197](https://arxiv.org/abs/2510.07197)}, 
}